The present application relates to a combined pressure control and lubricating valve for an hydraulically actuated friction engageable member such as is in transmission and brake mechanisms. It relates more particularly to a master clutch pressure and lubrication valve consolidating both such functions or services necessary for the power operated clutch, which clutch generally comprises a disc or plate pack that frictionally engages or disengages to control drive transmitted through a transmission as provided in tractor vehicles and other vehicles.
As background thereto, the material information includes but is not limited to U.S. Pat. Nos. 2,935,999, 3,125,201, 3,181,385, 3,352,392, 3,444,968, 3,498,150, 3,033,333, 3,583,422, 3,618,424, 3,882,738, 3,991,865, 3,998,111, 4,000,795, 4,015,619, 4,046,162, 4,216,851, 4,287,813, and especially U.S. Pat. No. 4,134,483 which was formerly assigned to the assignee hereof.
Power clutches and specifically hydraulic-power-clutches which receive their actuation control from a clutch pressure device and receive their cooling from a lubrication control device are in general use. Coordination between the two devices is required and similarly the provision of all required separate lines and connections, all in the effort to insure the necessary consersation of cooling lubrication oil at times when the clutch pack can have stabilized against further clutch slip, but at times otherwise to insure a liberal flow of the cooling oil. The physical separation of the devices is of course accommodated in actual practice, but involves interconnection and separate connection problems and other problems.